The present invention relates to the manufacture of tampons and has to do more particularly with the formation of closed tubular overwraps or sacks, as they will be referred to herein, containing an absorptive aggregate. Tampons of the type with which this invention is concerned are fully disclosed in commonly owned U.S. Pat. No. 3,815,601 of Jean E. Schaefer entitled "Catamenial Aggregate Absorbent Body" which issued on June 11, 1974. In accordance with the teachings of the said patent, the tampon comprises an aggregate composed of individual pieces of absorbent, foam-like material encased within a flexible, fluid-permeable overwrap. The overwrap is in the nature of a tubular sack closed at its opposite ends, the ends of the sack preferably being gathered inwardly and secured to form end seals. A withdrawal string is attached to one end of the sack, whereupon the sack which is preferably elongated, is formed into rosette shape by displacing the distal end of the sack inwardly, i.e., the end of the sack opposite the withdrawal string is displaced inwardly relative to the longitudinal axis of the sack to form a cavity in the overwrap. This forms a tampon structure in which the absorbent aggregate is encased by an overwrap having an exterior portion forming the exterior surface of the tampon and a re-entrant portion forming the surface of the cavity. Subsequent to the formation of the tampon into rosette shape, it is radially compressed and enclosed in a tube-type inserter by means of which it can be inserted into a vagina, as will be understood by those familiar with the tampon art.
The present invention is concerned with apparatus and procedures for forming and filling the tubular sacks in a continuous operation, commencing with a continuous web of sack-forming material which is pre-glued, tubed, and the tubing formed into a continuous series of filled sacks which are in condition to be conveyed to additional processing apparatus for the completion of the manufacturing operations, including the application of the withdrawal strings and the severance of the sacks into individual units, followed by their formation into the desired rosette shape and insertion into their dispensing tubes.
It is to be understood at the outset that the present invention, while directed specifically to the manufacture of tampons of the character described, will find utility in other applications wherein it is desired to package measured increments of material in a closed and sealed sack or overwrap. Consequently, while the invention will be described in connection with the manufacture of tampons, it should be readily apparent that the invention will have utility in other fields wherein a similar type of package is desired.